1 //===-- Hexagon.cpp -------------------------------------------------------===// 2 // 3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 4 // See https://llvm.org/LICENSE.txt for license information. 5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 6 // 7 //===----------------------------------------------------------------------===// 8 9 #include "InputFiles.h" 10 #include "Symbols.h" 11 #include "SyntheticSections.h" 12 #include "Target.h" 13 #include "lld/Common/ErrorHandler.h" 14 #include "llvm/BinaryFormat/ELF.h" 15 #include "llvm/Object/ELF.h" 16 #include "llvm/Support/Endian.h" 17 18 using namespace llvm; 19 using namespace llvm::object; 20 using namespace llvm::support::endian; 21 using namespace llvm::ELF; 22 23 namespace lld { 24 namespace elf { 25 26 namespace { 27 class Hexagon final : public TargetInfo { 28 public: 29 Hexagon(); 30 uint32_t calcEFlags() const override; 31 RelExpr getRelExpr(RelType type, const Symbol &s, 32 const uint8_t *loc) const override; 33 RelType getDynRel(RelType type) const override; 34 void relocateOne(uint8_t *loc, RelType type, uint64_t val) const override; 35 void writePltHeader(uint8_t *buf) const override; 36 void writePlt(uint8_t *buf, const Symbol &sym, 37 uint64_t pltEntryAddr) const override; 38 }; 39 } // namespace 40 41 Hexagon::Hexagon() { 42 pltRel = R_HEX_JMP_SLOT; 43 relativeRel = R_HEX_RELATIVE; 44 gotRel = R_HEX_GLOB_DAT; 45 symbolicRel = R_HEX_32; 46 47 // The zero'th GOT entry is reserved for the address of _DYNAMIC. The 48 // next 3 are reserved for the dynamic loader. 49 gotPltHeaderEntriesNum = 4; 50 51 pltEntrySize = 16; 52 pltHeaderSize = 32; 53 54 // Hexagon Linux uses 64K pages by default. 55 defaultMaxPageSize = 0x10000; 56 noneRel = R_HEX_NONE; 57 tlsGotRel = R_HEX_TPREL_32; 58 } 59 60 uint32_t Hexagon::calcEFlags() const { 61 assert(!objectFiles.empty()); 62 63 // The architecture revision must always be equal to or greater than 64 // greatest revision in the list of inputs. 65 uint32_t ret = 0; 66 for (InputFile *f : objectFiles) { 67 uint32_t eflags = cast<ObjFile<ELF32LE>>(f)->getObj().getHeader()->e_flags; 68 if (eflags > ret) 69 ret = eflags; 70 } 71 return ret; 72 } 73 74 static uint32_t applyMask(uint32_t mask, uint32_t data) { 75 uint32_t result = 0; 76 size_t off = 0; 77 78 for (size_t bit = 0; bit != 32; ++bit) { 79 uint32_t valBit = (data >> off) & 1; 80 uint32_t maskBit = (mask >> bit) & 1; 81 if (maskBit) { 82 result |= (valBit << bit); 83 ++off; 84 } 85 } 86 return result; 87 } 88 89 RelExpr Hexagon::getRelExpr(RelType type, const Symbol &s, 90 const uint8_t *loc) const { 91 switch (type) { 92 case R_HEX_NONE: 93 return R_NONE; 94 case R_HEX_6_X: 95 case R_HEX_8_X: 96 case R_HEX_9_X: 97 case R_HEX_10_X: 98 case R_HEX_11_X: 99 case R_HEX_12_X: 100 case R_HEX_16_X: 101 case R_HEX_32: 102 case R_HEX_32_6_X: 103 case R_HEX_HI16: 104 case R_HEX_LO16: 105 return R_ABS; 106 case R_HEX_B9_PCREL: 107 case R_HEX_B13_PCREL: 108 case R_HEX_B15_PCREL: 109 case R_HEX_6_PCREL_X: 110 case R_HEX_32_PCREL: 111 return R_PC; 112 case R_HEX_B9_PCREL_X: 113 case R_HEX_B15_PCREL_X: 114 case R_HEX_B22_PCREL: 115 case R_HEX_PLT_B22_PCREL: 116 case R_HEX_B22_PCREL_X: 117 case R_HEX_B32_PCREL_X: 118 return R_PLT_PC; 119 case R_HEX_IE_32_6_X: 120 case R_HEX_IE_16_X: 121 case R_HEX_IE_HI16: 122 case R_HEX_IE_LO16: 123 return R_GOT; 124 case R_HEX_GOTREL_11_X: 125 case R_HEX_GOTREL_16_X: 126 case R_HEX_GOTREL_32_6_X: 127 case R_HEX_GOTREL_HI16: 128 case R_HEX_GOTREL_LO16: 129 return R_GOTPLTREL; 130 case R_HEX_GOT_11_X: 131 case R_HEX_GOT_16_X: 132 case R_HEX_GOT_32_6_X: 133 return R_GOTPLT; 134 case R_HEX_IE_GOT_11_X: 135 case R_HEX_IE_GOT_16_X: 136 case R_HEX_IE_GOT_32_6_X: 137 case R_HEX_IE_GOT_HI16: 138 case R_HEX_IE_GOT_LO16: 139 config->hasStaticTlsModel = true; 140 return R_GOTPLT; 141 case R_HEX_TPREL_11_X: 142 case R_HEX_TPREL_16: 143 case R_HEX_TPREL_16_X: 144 case R_HEX_TPREL_32_6_X: 145 case R_HEX_TPREL_HI16: 146 case R_HEX_TPREL_LO16: 147 return R_TLS; 148 default: 149 error(getErrorLocation(loc) + "unknown relocation (" + Twine(type) + 150 ") against symbol " + toString(s)); 151 return R_NONE; 152 } 153 } 154 155 static uint32_t findMaskR6(uint32_t insn) { 156 // There are (arguably too) many relocation masks for the DSP's 157 // R_HEX_6_X type. The table below is used to select the correct mask 158 // for the given instruction. 159 struct InstructionMask { 160 uint32_t cmpMask; 161 uint32_t relocMask; 162 }; 163 164 static const InstructionMask r6[] = { 165 {0x38000000, 0x0000201f}, {0x39000000, 0x0000201f}, 166 {0x3e000000, 0x00001f80}, {0x3f000000, 0x00001f80}, 167 {0x40000000, 0x000020f8}, {0x41000000, 0x000007e0}, 168 {0x42000000, 0x000020f8}, {0x43000000, 0x000007e0}, 169 {0x44000000, 0x000020f8}, {0x45000000, 0x000007e0}, 170 {0x46000000, 0x000020f8}, {0x47000000, 0x000007e0}, 171 {0x6a000000, 0x00001f80}, {0x7c000000, 0x001f2000}, 172 {0x9a000000, 0x00000f60}, {0x9b000000, 0x00000f60}, 173 {0x9c000000, 0x00000f60}, {0x9d000000, 0x00000f60}, 174 {0x9f000000, 0x001f0100}, {0xab000000, 0x0000003f}, 175 {0xad000000, 0x0000003f}, {0xaf000000, 0x00030078}, 176 {0xd7000000, 0x006020e0}, {0xd8000000, 0x006020e0}, 177 {0xdb000000, 0x006020e0}, {0xdf000000, 0x006020e0}}; 178 179 // Duplex forms have a fixed mask and parse bits 15:14 are always 180 // zero. Non-duplex insns will always have at least one bit set in the 181 // parse field. 182 if ((0xC000 & insn) == 0x0) 183 return 0x03f00000; 184 185 for (InstructionMask i : r6) 186 if ((0xff000000 & insn) == i.cmpMask) 187 return i.relocMask; 188 189 error("unrecognized instruction for R_HEX_6 relocation: 0x" + 190 utohexstr(insn)); 191 return 0; 192 } 193 194 static uint32_t findMaskR8(uint32_t insn) { 195 if ((0xff000000 & insn) == 0xde000000) 196 return 0x00e020e8; 197 if ((0xff000000 & insn) == 0x3c000000) 198 return 0x0000207f; 199 return 0x00001fe0; 200 } 201 202 static uint32_t findMaskR11(uint32_t insn) { 203 if ((0xff000000 & insn) == 0xa1000000) 204 return 0x060020ff; 205 return 0x06003fe0; 206 } 207 208 static uint32_t findMaskR16(uint32_t insn) { 209 if ((0xff000000 & insn) == 0x48000000) 210 return 0x061f20ff; 211 if ((0xff000000 & insn) == 0x49000000) 212 return 0x061f3fe0; 213 if ((0xff000000 & insn) == 0x78000000) 214 return 0x00df3fe0; 215 if ((0xff000000 & insn) == 0xb0000000) 216 return 0x0fe03fe0; 217 218 error("unrecognized instruction for R_HEX_16_X relocation: 0x" + 219 utohexstr(insn)); 220 return 0; 221 } 222 223 static void or32le(uint8_t *p, int32_t v) { write32le(p, read32le(p) | v); } 224 225 void Hexagon::relocateOne(uint8_t *loc, RelType type, uint64_t val) const { 226 switch (type) { 227 case R_HEX_NONE: 228 break; 229 case R_HEX_6_PCREL_X: 230 case R_HEX_6_X: 231 or32le(loc, applyMask(findMaskR6(read32le(loc)), val)); 232 break; 233 case R_HEX_8_X: 234 or32le(loc, applyMask(findMaskR8(read32le(loc)), val)); 235 break; 236 case R_HEX_9_X: 237 or32le(loc, applyMask(0x00003fe0, val & 0x3f)); 238 break; 239 case R_HEX_10_X: 240 or32le(loc, applyMask(0x00203fe0, val & 0x3f)); 241 break; 242 case R_HEX_11_X: 243 case R_HEX_IE_GOT_11_X: 244 case R_HEX_GOT_11_X: 245 case R_HEX_GOTREL_11_X: 246 case R_HEX_TPREL_11_X: 247 or32le(loc, applyMask(findMaskR11(read32le(loc)), val & 0x3f)); 248 break; 249 case R_HEX_12_X: 250 or32le(loc, applyMask(0x000007e0, val)); 251 break; 252 case R_HEX_16_X: // These relocs only have 6 effective bits. 253 case R_HEX_IE_16_X: 254 case R_HEX_IE_GOT_16_X: 255 case R_HEX_GOT_16_X: 256 case R_HEX_GOTREL_16_X: 257 case R_HEX_TPREL_16_X: 258 or32le(loc, applyMask(findMaskR16(read32le(loc)), val & 0x3f)); 259 break; 260 case R_HEX_TPREL_16: 261 or32le(loc, applyMask(findMaskR16(read32le(loc)), val & 0xffff)); 262 break; 263 case R_HEX_32: 264 case R_HEX_32_PCREL: 265 or32le(loc, val); 266 break; 267 case R_HEX_32_6_X: 268 case R_HEX_GOT_32_6_X: 269 case R_HEX_GOTREL_32_6_X: 270 case R_HEX_IE_GOT_32_6_X: 271 case R_HEX_IE_32_6_X: 272 case R_HEX_TPREL_32_6_X: 273 or32le(loc, applyMask(0x0fff3fff, val >> 6)); 274 break; 275 case R_HEX_B9_PCREL: 276 checkInt(loc, val, 11, type); 277 or32le(loc, applyMask(0x003000fe, val >> 2)); 278 break; 279 case R_HEX_B9_PCREL_X: 280 or32le(loc, applyMask(0x003000fe, val & 0x3f)); 281 break; 282 case R_HEX_B13_PCREL: 283 checkInt(loc, val, 15, type); 284 or32le(loc, applyMask(0x00202ffe, val >> 2)); 285 break; 286 case R_HEX_B15_PCREL: 287 checkInt(loc, val, 17, type); 288 or32le(loc, applyMask(0x00df20fe, val >> 2)); 289 break; 290 case R_HEX_B15_PCREL_X: 291 or32le(loc, applyMask(0x00df20fe, val & 0x3f)); 292 break; 293 case R_HEX_B22_PCREL: 294 case R_HEX_PLT_B22_PCREL: 295 checkInt(loc, val, 22, type); 296 or32le(loc, applyMask(0x1ff3ffe, val >> 2)); 297 break; 298 case R_HEX_B22_PCREL_X: 299 or32le(loc, applyMask(0x1ff3ffe, val & 0x3f)); 300 break; 301 case R_HEX_B32_PCREL_X: 302 or32le(loc, applyMask(0x0fff3fff, val >> 6)); 303 break; 304 case R_HEX_GOTREL_HI16: 305 case R_HEX_HI16: 306 case R_HEX_IE_GOT_HI16: 307 case R_HEX_IE_HI16: 308 case R_HEX_TPREL_HI16: 309 or32le(loc, applyMask(0x00c03fff, val >> 16)); 310 break; 311 case R_HEX_GOTREL_LO16: 312 case R_HEX_LO16: 313 case R_HEX_IE_GOT_LO16: 314 case R_HEX_IE_LO16: 315 case R_HEX_TPREL_LO16: 316 or32le(loc, applyMask(0x00c03fff, val)); 317 break; 318 default: 319 llvm_unreachable("unknown relocation"); 320 } 321 } 322 323 void Hexagon::writePltHeader(uint8_t *buf) const { 324 const uint8_t pltData[] = { 325 0x00, 0x40, 0x00, 0x00, // { immext (#0) 326 0x1c, 0xc0, 0x49, 0x6a, // r28 = add (pc, ##GOT0@PCREL) } # @GOT0 327 0x0e, 0x42, 0x9c, 0xe2, // { r14 -= add (r28, #16) # offset of GOTn 328 0x4f, 0x40, 0x9c, 0x91, // r15 = memw (r28 + #8) # object ID at GOT2 329 0x3c, 0xc0, 0x9c, 0x91, // r28 = memw (r28 + #4) }# dynamic link at GOT1 330 0x0e, 0x42, 0x0e, 0x8c, // { r14 = asr (r14, #2) # index of PLTn 331 0x00, 0xc0, 0x9c, 0x52, // jumpr r28 } # call dynamic linker 332 0x0c, 0xdb, 0x00, 0x54, // trap0(#0xdb) # bring plt0 into 16byte alignment 333 }; 334 memcpy(buf, pltData, sizeof(pltData)); 335 336 // Offset from PLT0 to the GOT. 337 uint64_t off = in.gotPlt->getVA() - in.plt->getVA(); 338 relocateOne(buf, R_HEX_B32_PCREL_X, off); 339 relocateOne(buf + 4, R_HEX_6_PCREL_X, off); 340 } 341 342 void Hexagon::writePlt(uint8_t *buf, const Symbol &sym, 343 uint64_t pltEntryAddr) const { 344 const uint8_t inst[] = { 345 0x00, 0x40, 0x00, 0x00, // { immext (#0) 346 0x0e, 0xc0, 0x49, 0x6a, // r14 = add (pc, ##GOTn@PCREL) } 347 0x1c, 0xc0, 0x8e, 0x91, // r28 = memw (r14) 348 0x00, 0xc0, 0x9c, 0x52, // jumpr r28 349 }; 350 memcpy(buf, inst, sizeof(inst)); 351 352 uint64_t gotPltEntryAddr = sym.getGotPltVA(); 353 relocateOne(buf, R_HEX_B32_PCREL_X, gotPltEntryAddr - pltEntryAddr); 354 relocateOne(buf + 4, R_HEX_6_PCREL_X, gotPltEntryAddr - pltEntryAddr); 355 } 356 357 RelType Hexagon::getDynRel(RelType type) const { 358 if (type == R_HEX_32) 359 return type; 360 return R_HEX_NONE; 361 } 362 363 TargetInfo *getHexagonTargetInfo() { 364 static Hexagon target; 365 return ⌖ 366 } 367 368 } // namespace elf 369 } // namespace lld 370